Curse of the Pharoahs Achievements
Pyromaniac – Burn a mummy to death. Or redeath. Mummies can be found as soldiers in the Afterlifes, sometimes as guards, but more usually as officers. Mummies can also be found guarding the Temple of Karnak during the last leg of the Curse of the Pharaohs main quest. Get this achievement by killing one with fire. Note that a fire-arrow kill isn't enough- it has to be the burning damage itself that knocks it down to 0 hp.
Dark Horse – After visiting the afterlife and summoning a mount there, go to the Set Maat stables in the real world and purchase the same horse- Eternal Maw. Which makes sense to Bayek, one supposes, but what did the horse-seller thing when the Maw just appeared in his stables one morning? Dressed like that?
Sting in the Tail – Complete the five Serquet Locations: Serquets's Altar in Aaru, Serquet's Garden in Aten. Serquet's Chamber in Heb Sed,the Halls of Serquet in the Duat, and the Spring of Serquet in the real world. This also unlocks the Serquet's Carapace armor.
Project Comet – Craft an upgrade using Shards of a Star. You can find enough for your first upgrade in the white chest at the Nut's Gift location when you first reach Aaru.
Higher Power– Reach Level 55. Completing all the objectives in the DLC should get you here easily, without additional grinding.
Lift the Curse – Defeat Tutankhamun at the end of the Curse of the Pharaohs main quest (you do not need to have completed the King of Kings main quest for this achievement).